I was just wondering if it was possible to, let's say, fly international carriers on domestic routes. I've searched many booking sites and I didn't see that kind of option. For example, would it be possible to fly on Qantas JFK-LAX? Or SUJFK-IAD? If so, how do you get tickets. If no, why not? I'm sure someone out there knows the answer.

A mile of runway takes you to the world. A mile of highway takes you a mile.

AC has been trying to get approval to serve points wihtin the US. and the Canadian government wouldn't mind it even though it will mean US carriers would serve points in Canada. The US government wouldn't approve it, because they would have to allow European carreisr to do the same. BUT it's impossible to get serive rights within Europe for an US carrier

The US government wouldn't approve it, because they would have to allow European carreisr to do the same.

That's not the reason. AC would like to fly American passengers from one USA city to another via its YYZ hub... in return they'd allow US-flag carriers to fly Canadian passengers from one Canadian city to another via their USA hubs... but the USA feels the deal would be more lucrative to AC than US-flag carriers...

But what about American airlines, such as PanAm or TWA having hubs in Europe? If someone in Europe was able to fly TWA from Athens to Rome, why wouldn't someone in America be able to fly let's say El-Al EWR-MIA

A mile of runway takes you to the world. A mile of highway takes you a mile.

Pan Am and TWA were allowed to fly those routes back then because the 'home' airlines did not have the international presence that PA and TW enjoyed. Remember, Pan Am was not allowed domestic routes in the United States because it was considered an 'international airline'. And since the US Government considered it an international airline, then the other countries did also. On the other hand, TWA somehow got special treatment on domestic routes (before deregulation), but as the years progressed (especially after deregulation) they cancelled many international destinations.

That brings us to the current situation. After Pan Am and TWA, no other airline has enjoyed the benefits of flying such routes or of having such an international presence. (I know UA and NW both have Tokyo hubs, but nothing as extensive as what PA and TW had!)

Most important though, I agree basically with what you said. I think foreign airlines should be allowed to fly US domestic routes (as long as US airlines are provided the same courtesy). BUT, one thing does concern me - that the foreign airlines would only cherry pick the most lucrative routes and that would force the major US airlines to abandon some smaller cities because of the financial difficulties stemming from such actions. (Kind of like what the LCC's are doing, but on a much larger scale!)

That's only part of it. The true open skies would allow AC (or its subsidiary) to opearte say LAX-SFO.AC knew that was extreme... JFK-LAX is a heck of a lot more lucrative than YYZ-YVR ... they would've accepted an agreement that allowed them to trasnfer USA passengers via its Canadian hubs.

...would be a win-win situation for everyone.
It'd favor AC more, since the USA market is more lucrative than the Canadian market...

There used to be flights with CI or CA from ANC to JFK...
Now that was already some years ago I guess, but weren't people able to buy tickets for just that leg or did you have to have say TPE-ANC-JFK tickets?
Also, in Canada didn't CX fly YVR-YYZ as continuation of their HKG flight?

But what about American airlines, such as PanAm or TWA having hubs in Europe? If someone in Europe was able to fly TWA from Athens to Rome, why wouldn't someone in America be able to fly let's say El-Al EWR-MIA

Athens and Rome are in two different countries, Miami and Newark are not. None the less, that was a long time ago. Until very recently (a few days ago), United flew daily between London Heathrow and Brussels. They were not allowed to carry local traffic (all of the countries of the EU, plus Switzerland and Norway, are now considered a sort of giant domestic market). American Airlines flies daily between Sao Paulo and Belo Horizonte in Brazil, and, again, zero traffic rights. Technically, however, one can fly, for example, between Miami and Newark on El Al. Purchase an MIA-TLV ticket with an extended layover in Newark and just don't bother to show up for the EWR-TLV segment. Sure will cost a lot more than just hopping on AA, but you'll get to fly a 772 or 744.